I've had my ARC Classic 60 driving my Thiel CS 3.5's for over 30 years. Superb match and I've never been tempted to change. It's fed with an ARC SP 9 mk III. Never had upgrade-itis other than one change in cables. So happy my dealer helped with this pairing as I get to just enjoy it. Sure, love to hear different things, but system synergy rules! Probably saved me a fortune. At this point, getting concerned with age of caps and what to do about it.
Old Amps that can still Kick Butt
Not being a believer that time necessarily = progress, I would like to offer the following example of a sonic gem that has transcended time and can totally kick butt in a modern milieu:
The Robertson 4010. I got one of these about two years ago because it was in immaculate condition, the price was so low and I was inquisitive. I hooked it up and let it warm up for a couple of days. OMG this thing was in the super amp league: Transparency to die for, slam that you couldn‘t‘ believe for for a 50W amp.. Peter Moncrieffe wasn‘t wrong in his review of this amp: this thing is in the Sterreophile Class A component category hands down. Even after all these years.
What amps have you encountered that have defied time and can still kick butt today?